Regeneration of the absorbent solution laden with acid compounds is costly, notably as regards energy consumption. This is a major drawback, notably when the absorbent solution is used to collect the CO2 present in combustion fumes. In fact, although the heat required to regenerate the absorbent solution is obtained by combustion of a fossil fuel, an additional amount of CO2 that would make the collection of CO2 by absorption uninteresting may be produced.
The present invention aims to fractionate the absorbent solution laden with acid compounds into two parts, a fraction rich in acid compounds and a fraction poor in acid compounds, and to regenerate by distillation only the fraction that is enriched in acid. compounds in order to minimize the energy required for regeneration of the absorbent solution.